Japanese laid-open Patent Publication No. 2004-154903 discloses an electric hammer having a vibration reducing mechanism. This known electric hammer has a dynamic vibration reducer as a means for reducing vibration caused in an axial direction of a hammer bit during hammering operation, so that vibration of the hammer during hammering operation can be alleviated or reduced. The dynamic vibration reducer has a weight which can linearly move under a biasing force of a coil spring, and by the movement of the weight in the axial direction of the tool bit, it reduces vibration of the hammer during hammering operation.
In designing a power tool of this type having a dynamic vibration reducer, it is desired to provide a technique which can realize rational placement of the dynamic vibration reducer and a higher vibration reducing effect or higher vibration reducing performance of the dynamic vibration reducer, by further refinement of the construction of the dynamic vibration reducer.